Wells that are in production are prone to occasional production of undesirable water or unwanted gasses such as methane, for example. When these situations arise it is necessary to cut the production flow and take production from elsewhere in the wellbore or even to drill a new lateral to get away from the migration of those contaminants into the production string.
Typically, the production takes place through screens, with or without a gravel pack in the annulus around the screen. In the event of production of a contaminant, it is advantageous to cut off the production flow and to do it automatically at the initial detection of the presence of such a material.
The present invention has many applications and is suited to selectively cut off flow to a screen section where the foreign material is sensed. It can be employed with an Equalizer® Screen sold by Baker Oil Tools or with other tools. In the preferred embodiment a shape memory material that is sensitive to the presence of the undesired contaminant is used to hold in a check an energy source. Once the contaminant is detected the material properties of the shape memory material change and the potential energy is liberated to allow flow to be blocked. Those skilled in the art will appreciate that other applications or the reverse of the preferred operation are also envisioned and that the full scope of the invention is given by the claims that appear below.